On this web-site you will find information about using electrical equipment designed for a certain frequency on an other frequency.

Alternating current (AC) starts at the powerplant and the unit of frequency is Hertz (Hz) which is the amount of cycles
per second the voltage or current changes in value from plus to zero to minus to zero to plus etc.

In some English spoken countries it is expressed in cycles per second (cps).

Nowedays Hertz is the official unit of expression.

Transformers and AC-electric motors only function because of these cycles.

In the world there are basically two frequencies used for normal electrical use: